Transfer activity coefficients of ortho-substituted and non-ortho-substituted benzoates between water, methanol, and polar aprotic solvents

1974 ◽  
Vol 78 (8) ◽  
pp. 839-846 ◽  
Author(s):  
M. K. Chantooni ◽  
I. M. Kolthoff

1983 ◽  
Vol 36 (9) ◽  
pp. 1753 ◽  
Author(s):  
Jr MK Chantooni ◽  
IM Kolthoff ◽  
G Roland

Stability constants, Kf(LK+) and Kf(LKX) = [LKX]/[L][KX] at 25� in the dipolar aprotic solvents acetone (Me2CO), acetonitrile (MeCN), propylene carbonate (pc), N,N-dimethylformamide (HCONMe2), dimethyl sulfoxide (Me2SO), as well as in the alcohols, methanol (MeOH), isopropyl alcohol (Pr1OH), and butan -1-ol (BuOH) have been determined, L being bis(4,4'(5')-t-buty1benzo)-18- crown-6 (di(BuBo)-18-cr-6). This crown is considerably more lipophylic than is dibenzo-18-crown-6. Values of Kf(LKX) have been found from values of Kf(LK+), KA(KX) and KA(LKX). Transfer activity coefficients, Me2COγS, have been calculated (based on the Parker proposal that γ(Ph4As+) = γ(BPh4-) between acetone and the various solvents used of K+, Br-, ClO4-, P1- (picrate), LK+, KX, and LKX. It is found that K+ is more strongly solvated in Me2CO than in the other aprotic solvents of low donicity. The reverse is true between Me2CO and HCONMe2 or Me2SO (even after correcting for the Born effect).



1983 ◽  
Vol 36 (9) ◽  
pp. 1767 ◽  
Author(s):  
SS Goldberg ◽  
O Popovych

Transfer activity coefficients for the sodium ion, logmγNa, between pairs of dipolar aprotic solvents were estimated from the e.m.f. of cells consisting of two sodium-selective electrodes in different solvents connected by a salt-bridge of triisoamylbutylammonium tetraphenylborate [(tab+)BPh4-], or tetraethylammonium picrate (Et4NPic), or tetraethylammonium perchlorate (Et4NclO4). The solvents were: acetonitrile (MeCN), N,N-dimethylformamide (HCONMe2), dimethyl sulfoxide (Me2SO), propylene carbonate (pcar), and N-methylformamide (HCONHMe). Values of logmγNA were estimated first by neglecting the liquid-junction potential E, and then, for some systems, by applying an Ej correction from theory. A novel method of estimating transfer activity coefficients for single ions, based on the Ej equation, was demonstrated on the (tab+) and Pic-ions. Transfer activity coefficients for the hydrogen ion between MeCN and HCONMe2 as well as MeCN and Me2SO were similarly estimated from the e.m.f. of two pH (glass) electrodes immersed in buffer media in the above pairs of solvents.



1975 ◽  
Vol 28 (9) ◽  
pp. 1907 ◽  
Author(s):  
STD Lo ◽  
DW Watts

The displacement of the coordinated Me2SO from [Cr(NCS)5(Me2SO)]2- by NCS- and pyridine has been studied in the solvent tetramethylene sulphone (sulpholane). The results are consistent with a limiting dissociative mechanism. The solvolysis reactions: �� ��������������[Cr(NCS)6]3- + sol → [Cr(NCS)5(sol)]2- + NCS- have been studied in the solvents (sol) Me2SO, HCONMe2 and MeCONMe2. The transition states for these solvolysis reactions are compared with a dissociative model ������������������������ [Cr(NCS)5(3-)+(∂+)...NCS∂-] by means of solvent transfer activity coefficients. Kinetic and activation data are recorded for a number of solvent interchange reactions: ����������� [Cr(NCS)5(sol1)]2- + sol2 → [Cr(NCS)5(sol2)]2- + sol1



1986 ◽  
Vol 64 (3) ◽  
pp. 608-614 ◽  
Author(s):  
C. Louis ◽  
J. Bessière

Solvation properties of ions inH2O–H3PO4 media (1–14 M) are characterized with their solvation transfer activity coefficients f. These are calculated from normal potential or solubility values, and indicate an increasing solvation for anions and decreasing solvation for cations in concentrated acid solutions. For each species, the range depends on its number of charges, on the existence of oxygen atoms in its structure, and on its basic properties. The consequences of variation of solvation on oxidation–reduction reactions and solubility properties are studied.





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